12kv-switchgear.pdf

12kV DOUBLE BUSBAR SWITCHGEAR INSTRUCTION AND OPERATION MANUAL (HICLAD- 10D)

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EPE POWEll CORPORATION BERHAD (Company No. 12351-K)

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LOT 1296, BATU 5, JALAN IPOH, 51200 KUALA LUMPUR

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OPERATION

& INSTRUCTION MANUAL 11kV DOUBLE BUSBAR SWITCHGEAR HICLAD 100

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EXCLUSIVE RIGHT

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The policy of EPE POWER CORPORATION BERHAD.

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Is one of continuous Improvement and Development. The company therefore reserve the right to supply equipment which may differ slightly from that described and illustrated in this publication.

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CONTENTS

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ITEM

1. 2. 3. 4. 5. 6.

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8. 9.

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11.

TITLE

Introduction Ratings Structure of the cubicle Despatch Storage Installation 6-1. Unpacking 6-2. Handling 6-3. Preparing The Foundation Floor 6-4. Erection Procedure 6-5. Extension To Existing Switchgear 6-6. Connection Of Earthing Busbars 6-7. Connection Of Control Wirings 6-8. Power Cable Termination 6-9. Protection Against Vermin Entry 6-10. Busbar Connections 6-11. Inspection After Installation Operation 7-1. VCB Operation 7-2. Earthing Switch 7-3. Interlocks Safety Shutters Test And Commisioning 9-1. General 9-2. Physical Inspection 9-3. Isulation Resistance Test 9-4. Power Frequency Voltage Withstand Test 9-5. Relay Injection Test 9-6. Operation Test 9-7. Final Check Maintenance 10-1. General 10-2. Types Of Inspection 10-3. Methods Of Inspection 10-4. Safety Precautions 10-5. Check Of Paintwork Troubleshooting

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2 5 5 6 6 6 7 12 14 14 14 15 17

19a 20 20 20 22 22 22 23 23 23 24 24 25 26 26 26 26 27

28 29 29 30

VFT-lOD Rev No: 0

1.0 INTRODUCTION The purpose of this instruction manual is to provide guidelines for operation and maintenance of the high voltage metal clad double busbar switchgear (HICLAD lOD). The operation and maintenance procedures of vacuum circuit breaker (VCB) should be referred to it's instruction manual.

2.0 RATINGS The standard ratings of the 12kV Double Busbar Metal clad manufactured by EPE switchgear are shown in Table 2.1.

~ Type

HICLAD- lOD

Applicable Standard

IEC 298, BS 5227

Rated voltage (kV)

12

Rated Frequency (Hz)

50 or 60 800,1250, 2000

Rated Current (A) ofVCB Rated Current (A)

up to 2000

of Busbar Short Time Rating

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(a) Current

25 kA

(b) Time

3 sec

Insulation Level

Insulation Level

(a) Impulse (kV)

75

(b) AC (kV)

28

Type of VCB

VFT- 12D ~------

Table 2.1 Standard Ratings

VFf-lOD Rev No: 0

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3.0 STRUCTURE OF THE CUBICLE The HICLAD lOD double busbar switchgear is designed and constructed in such a way that it is a totally enclosed metal clad cubicle and in a compartmentalised pattern with insulated busbars and utilising the vacuum circuit breaker (VCB). The figure below shows the cross section of a typical panel.

VACUUM CIRCUIT BREAKER

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CURRENT TRANSFORMER (RING)

2a

CURRENT TRANSFORMER (RING)

2b

CURRENT TRANSFORMER (RING)

3

EARTHING SWITCH

4

CABLE TERMINATION BUSBAR

5

MAIN BUSBAR

5o

RESERVE BUSBAR

6

BUSBAR SUPPORTER

7

DROPPER CONNECTION

8

ISOLATING CONTACT

9

METAL SHUTTER

10

OPERATING MECHANISM FOR ES

11

TERMINAL BLOCK

12

CONTROL CIRCUIT CONNECTION FOR VCB

13

EARTH BUSBAR

14

PARTITION

14a

PARTITION

14b

PARTITION

15

POWER CABLE CLAMP

16

PRESSURE RELIEF FLAP

17

RELAY COMPARTMENT

18

MULTI CORE CONTROL CABLE BOX

19

5Jmm RAYCHEM TUBULAR CU. BUSBAR

20

CABLE TRUNKING

21

ANTI CONDENSATION HEATER

22

EARTH SWITCH CONNECTION

23

VOLTAGE DETACTOR

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Figure 3.1 Cross Sectional View Of A Typical HJCLAD JOD Panel For Single Three Core Cable Termination Design

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Figure 3.1, shows the switchgear design for single three core cable but in the case where three single core cables per phase are used, the termination busbars design is shown in the figure below.

VACUUM CIRCUIT BREAKER

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2

CURRENT TRANSFORMER (RING)

2a

CURRENT TRANSFORMER (RING)

2b

CURRENT TRANSFORMER (RING)

3

f.ARTHING SWITCH

4

CABLE TERMINATION BUSBAR

5

MAIN Bl.ISBAR

Sa

RESERVE BUSBAR

6

BUSBAR SUPPORTER

7

[lRUPPER CONNECTION

8

1'30LATING CONTACT

9

METAL ')HUTTER

10

OPERATING MECHANISM FOR ES

11

TERMINAL BLOCV

12

CONTROL CIRCUIT CONNECTION FOR VCB

1.3

EARTH BUSBAR

14

PARTITION

14a

PARTITION

14b PARTITION 15

POWER CABLE CLAMP

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PRESSURE

17

RELAY COMPAr
18

MULTI CORE CONTROL CABLE BOX

19

53, nrn RA'fCHEM TUBULAR CU BUS BAR

20

CABLE TRUNKit
21

ANTI CONGENSATION HEATER

22

EARTH SWITCH CONNECTION

2J

VOLTAGE DETACTOR

F~EUEF

FLAP

23o SUPPORT INSULATOR 24

POTENTIAL TRAtEFORMER

25

PT. CONNECTION

26

PRIMARY FUSE

Figure 3.2 Cross Sectional View Of A Typical Hiclad JOD Panel For 3 Single Core Per-Phase Cables Termination Design

3

VFT-lOD Rev No: 0

VACUUM CIRCUIT BREAKER

2 .3

4 5

MAIN BUSBAR

5o

RESERVE BUSBAR

6

BUSBAR SUPPORTER

7

DROPPER CONNECTION

8

ISOLATING CONTACT

9

METAL SHUTIER

10

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11

TERMINAL BLOCK

12

CONTROL CIRCUIT CONNECTION FOR VCB

13

EARTH BUSBAR

14

PARTITION

14o

PARTITION

14b

PARTITION

15

POWER CABLE ClAMP

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PRESSURE RELIEF FlAP

17

RElAY COMPARTMENT

18

MULTI CORE CONTROL CABLE BOX

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CABLE TRUNKING

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ANT! CONDENSATION HEATER

22 23

VOLTAGE DETACTOR

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Figure 3.3 Cross Sectional View Of A Bus Section

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VFf-lOD Rev No: 0

VACUUM CIRCUIT BREAKER

2

CURRENT TRANSFORMER (RING)

3

4

5

MAIN BUSBAR

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RESERVE BUSBAR

6

8U38AR SUPPORTt:R

7

DROPPER CONNECTION

8

ISOLATING CONTACT

9

METAL SHUTTER

10 11

TERMINAL BLOCK

12

CONTROL CIRCUIT CONNECTION FOR VCB

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EARTH BUSBAP

14

PARTITION

14o

PARTITION

14b

PARTITION

15

16

PRESSURE RELIEF FLAP

17

RELAY COMPARTMENT

18

MULTI CORE CONTROL CABLE BOX

19

S)mm RE ICHEM TUBULAR CU.BUSBAR

20

CABLE TRUNKING

21

ANTI CONDENSATION HEATER

U"

23

SUPPORT INSULATOR

Figure 3.4 Cross Sectional View Of A Hiclad b

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VFf-lOD Rev No: 0

Item

Name

Qty.

Rating & Remark 630A 12kV 20kA 3 sec

1

Vacuum Circuit Breaker

1

2

Current Transformer

3

3

Earthing switch

4

Cable Termination Busbar

5

Main busbar

3 Ph

9

Bushing/Isolating Contact

3 Ph

10

Metal Shutter

I set

13

Control Circuit Connection

1 set 3

For VCB

630A

I set

23

Heater

2

27

Lifting Eye

4

28

Screen Plate

1

60 Watt !

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Table 3.1 Legend For The Cross Sectional View

With reference to the figure shown, the VCB compartment is located on the front of the

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cubicle. This compartment houses the circuit breaker which is of vertical isolation and horizontal withdrawal type with mechanical interlock features. Location of the circuit breaker truck within the compartment is made by moving the truck along the horizontal base rails. The LV metering, relay and instrumentation compartment is situated above the VCB compartment. The busbar and CT compartments are located in the middle of the switchgear cubicle. The CTs are mounted in between the top reserve busbars and the bottom main busbars. Busbar selection is made by vertical transfer of the circuit breaker to the appropriate position. Pressure relief flaps are provided on the top portion of the panel to ensure safety of the operator in the event of an explosion during fault occurance. These flaps are also provided in the arc conduit at each end of the panel for pressure relief of fault in the bottom busbars compartment. Independently operated safety shutters, cover the fixed isolating contact bushing orifices and are positively operated by the insertion or withdrawal of the circuit breaker truck. Each of the busbar or circuit shutters are padlockable at either the closed or for open maintenance or for testing purpose. Re-insertion of the circuit breaker into the housing automatically unable the catches. The secondary control wiring isolating contacts are of the plug and socket type. The plug (male) contacts are ·wired to the VCB control and fixed to the top of the truck. The fixed socket (female)

cont~cts

are wired to the control terminal blocks in the LV metering compartment. The

insertion of the plug contacts into the socket contacts is made by moving the VCB into its fully engaged position. To test the operation of the circuit breaker at the isolated position, a flexible "Test

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Cord" is provided. A fully interlocked integral earthing switch is incorporated in the HICLAD 1OD feeder panel for cable earthing during maintenance. A circuit connected voltage transformer can be mounted on the top rear portion of the panel. The VT is normally of the dry epoxy resin insulated type and is protected by primary and secondary fuses. It is firmly locked in it's service position by a latch. Automatic safety shutters are provided to cover the live contacts when the VT is isolated. The VT is mounted on a truck and is fully withdrawable. Fixed VT version is also available upon request. Interlocks are provided to ensure that the circuit breaker or earthing switch 1s properly and safely operated. Detailed descriptions of the interlocking features are given in section 7.3. Power cable entry is from the bottom as a standard. Adequete space is available for cable termination in : the cable compartment which is accessible through the removable rear covers. A multi-core cable - ' box is mounted at the rear of the panel. This allows termination of tfie

e-xternaTcohtro.tcable~ to

be carried out without interfering with the busbar and power cable compartments.

4.0 DESPATCH The switchgear panels are despatched in units or sections, depending on the conditions at site, with all the inter-connecting busbars supplied as loose items. The circuit breaker truck is placed in the engaged position within its compartment to prevent it from rolling out of the housing to avoid damage to the isolating contacts. In accordance to the manufacturer's recommendations, relays' movement are tied and induction discs are wedged during transportation. Indicating instrument movements are not secured. Each •

switchboard is supplied complete with the following items: a) Circuit breaker elevating handle(raising!lowering) b) Manual charging handle c) Earthing switch operating handle Test bushings and tool kits are supplied only when requested during placement of order. Note that these are optional items.

5.0 STORAGE The HICLAD 1OD '--.:!..

switch~ear

is meant for indoor operation and should be stored in a clean, dry

and ventilated environment. Unless otherwise specified, it is not weather proof and should not be left outdoor where rain and moisture may cause irreversible damage. For prolonged storage, it is recommended that the panel be energised to prevent moisture condensation. Cover the switchgear with plastic sheet to protect against dust settling and the surface panel from being scratched. Panel must be stored in a non-corrosive environment.

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VIT-lOD Rev No: 0

6.0 INSTALLATION 6.1 Unpacking Each unit or section is packed according to the type of delivery. On arrival at site, each part of the consignment should be checked with the relevant shipping document. Any shortage or damages should be reported within THREE (3) days of receipt to the forwarder AND either to EPE POWER CORPORATION BHD. or the agent who supplied the switchgear. Detailed descriptions of the part concerned and any damage incurred during transportation should also be included. Failure to do so may result in claim(s) not being entertained. 6.2 Handling After unpacking, care must be taken when handling the switchgear. The switchgear can be moved by using a crane, lifting hoist or rollers and levers. To facilitate lifting, removable lifting eyes/bolts are attached on the side panels of each shipping section. Before the panel is being lifted, make sure

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that the circuit breaker truck is held securely inside its compartment so that it will not roll out of the housing during lifting operations. A typical method of lifting is shown in Figure 6.2.1. The slings of the lifting ropes should be of equal lengths to allow easy balancing. When the switchgear units need to be rolled into their position, move the units carefully on three steel rollers of 25mm diameter, positioned so as to avoid flexing of the structure.

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VFT-lOD Rev No: 0 6

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Figure 6.2.1 Typical Method Of Lifting

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MAX TWO PANELS FOR ONE LIFTING (WHEN) COUPLED TOGETHER

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6.3 Preparing The Foundation Floor Every attention is given in the factory to ensure that the switchgear is accurately manufactured and that it should function properly and satisfactorily, provided it is properly erected at the site. It is jig assembled on level floor in the factory and to obtain satisfactory operation, these conditions should be reproduced at the site.

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6.3.1 Switchgear Panels Erected On Substation Floor

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It is essential that the foundation floor level must be fairly flat. If that floor is not level, the

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switchgear may be deformed during installation. This will cause damage or malfuction to the equipment. The basic requirements for correct erection are as follows: 1) The bottom plate of the unit must be flat and level as specified.

VFT-lOD Rev No: 0

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2) The sides of the basic housing must be vertical and particular attention should be paid to the front of the unit. 3) The longitudinal alignment and height of the units should be referred to the front of the housing and instrument panels. 4) The area of the substation floor of the switchgear must be flat and level to ensure that the circuit breaker truck is standing in a vertical position at the point of entry into the housing. 5) Care should also be taken when tightening down the foundation bolts, since excessive tightening will distort the bottom plate. It is usual, when cementing the grouting bolts in, to flood a 300 mm diameter pad of concrete, thus supporting the bottom plate. Provided that the floor level is within t 2mm in 1 meter, no difficulty will be experienced during erection.

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Notes for tightening the foundation bolts: 1) Insert liners if there is a gap between the foundation and the switchgear. 2) Unreasonable screwing of foundation bolts into bolt holes of the switchgear is absolutely prohibited if their size does not fit the size of the holes.

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All four foundation bolts must be used.

Foundation boll

Switchgear bottom

Finished floor surface

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Foundation

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Figure 6.3.1.2 Fixing The Foundation Bolt

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Figure 6.3.1.3 Level Adjustment

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6.3.2 Switchgear Panels Erected On Unistruts In the case where unistruts are embedded in the floor for the switchgear panels to be mounted on top of it, care must be taken to ensure that the clearance from the floor level to the switchgear panel is 5 mm or less.

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SWITCHGEAR BASE PLATE

UN !STRUT

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41.3 mm

Figure 6.3.2.1 Embedded Unistruts

~ith

Bolt-Spring Nuts

For erection of more than 1 panels, the unistruts must be embedded horizontally.

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SWITCHGEAR PANEL

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Figure 6.3.2.2 Plan View Of Panels Erected On Unistruts.

t The following points should be noted when installing the embedded unistruts: 1) Examine the mutual positioning and dimensions of the embedded bases and foundation bolts for the cubicle. Check the drawing to confirm that there is no abnormal bending.

VFf-lOD Rev No: 0

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2) Arrange the embedded unistruts according to their correct dimensions and positions. They must be arranged and fixed horizontally. Instruments for horizontal measurement need to be employed and the horizontal level must be determined precisely. 3) The unistruts must be fixed according to Figure 6.3.2.1 so that the alignment of the switchgear can be achieved.

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The horizontal level can be checked with a plumb bob and liners can be inserted to make sure that distance A and B are equal (Refer Figure 6.3.3.1). This level check is required in all direction, front,

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rear, left and right.

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6.3.3 Level Adjustment

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6.4 Erection Procedure Units or sections should be erected and coupled in the following manner: 1) Withdraw the circuit breaker from the housing to reduce weight. Refer section 7.3 for clarification.

VCB

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Figure 6.4.1 VCB Truck Withdrawn From Cubicle

2) The lifting eyes can be left on the panels or removed. 3) Bring the units together over the floor mounting holes or unistruts, lining up front edges and busbar centre. In case of a long switchgear panel, it is recommended to start erection from the center instead from one end of the panel. Once the correct horizontal level has been established, a neighbouring panel should be installed as closely as posible to the preceding switchgear. The horizontal level for this switchgear is also arranged in the same manner. NO GAP /

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Figure 6.4.2 Arrangement Of Switchgear

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4) When all the panels have been installed in alignment, they are rigidly tightened with bolts and nuts through their connecting holes provided on their panel sides. Clamping work between

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VFT-100 Rev No: 0

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panels must start from the center to the left and then from the center to the right. BASIC PANEL I

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5) Fix the bolts through the bottom plates of the panels to the floor or to the unistruts. Refer Figures 6.3.1.2 or 6.3.2.1.

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6) Remove covers from busbar chambers.

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7) Install busbar links, ensuring that joint surfaces are clean. Smear with a thin film of vaselin, if necessary. Tighten the bolts securely.

-~ 8) Replace covers of busbars chambers. 9) Connect the earth busbars. Refer to section 6.6. 10) Connect inter-panel control wirings. Refer to section 6.7.

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11) After the power cable termination have been completed, the VCB truck can be pushed into the cubicle again (refer section 7 .3).

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VFT-lOD Rev -No: 0

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Figure 6.4.4 VCB Truck Inserted Into Cubicle

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6.5 Extension To Existing Switchgear At each end of the panel, the end of the busbar chamber is blanked off using a steel arc conduit which is fitted with a pressure relief flap at the top. This flap will release the pressure in the event of any fault in the lower busbar compartment. When an existing switchgear is required to be extended, the new panel can be erected into position after removal of the conduit. By switching off the bus section and bus coupler circuit breakers and one of the incomers one side of the switchgear will be dead. Erection of the new panel can then be carried out on the dead end. In this way, loss of supply will only effect one half of the loads. Once all the busbar links are fitted between the existing and new panels, the substation will be ready for full re-energisation.

6.6 Connection Of Earthing Busbars

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Earthing busbar links separately supplied with the switchgear panel are to be installed along the rear within the cable compartment. Ensure that all joints between the earthing bar sections are accurately bolted. The connection to the station earthing system should have a cross-section not less than that of the earth bar mounted on the panels.

6.7 Connection Of Control Wirings Terminals for the connection of auxiliary control and other external wirings are provided in the multi-core box mounted at the rear of each panel. Remove the cover of the multi-core box of the terminal blocks. Complete the termination of the cables according to the relevant wiring diagrams.

VFT-lOD Rev No: 0

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Ensure that each cable is firmly and neatly terminated. Drill hole on the plate cover to match the diameter of the cable gland used to hold the cables. Inter-panel wirings should be made in the same manner, but the terminal blocks are located inside the LV relay and metering compartment.

6.8 Power Cable Termination Note: Any high voltage tests to be made on the switchgear should be performed before the power cables are terminated, otherwise temporary disconnection of the cables may be necessary. Cable contractors are best experienced in cable jointing. This manual does not gi"ve instructions relating to cable jointing since the methods varies from contractors to contractors and it also depends on the type of cable and termination used. For operation or installation procedures of the

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termination kits, please refer to the manufacturer's manual of the relevant type of termination kits used. To acess the cable chamber, firstly remove the rear covers. When cable termination have been completed, make sure that the cable chamber is cleaned of any debris and that no tool is left in the chamber. Finally replace the cover and make sure that the cover is tight.

CA~LE

TERMINATION

.J POWER CABLE

CABLE SUPPORT

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.•. CABLE TRENCH

Figure 6.8.1 Power Cable Termination For Single 3 Core Cable

VFT-IOD Rev No: 0

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$

$ CUT OUT FOR CABLE CABLE SUPPORT

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BRACKET

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Figure 6.8.2 Plan View Of cable Support And Gland Plate For Single 3 Core Cable

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CABLE TERMINATION POWER CABLE

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GLAND PLATE CABLE TRENCH

Figure 6.8.3 Power Cable Termination For 3 Single Core Per-phase cable

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VFf-lOD Rev No: 0

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CABLE SUPPORT CUT OUT _FOR CABLE

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CUT SEMICIRCLE ON EACH HALF

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OF GLAND PLATE

Figure 6.8.4 Plan View OfCable Support And Gland Plate For 3 Single Core Per-phase Cables.

6.9 Protection Against Vermin Entry To prevent the instrusion of vermins like rats, snakes and other insects, cover the main cable entry

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opening using the gland plate provided. The cable gland plates are divided into two parts per-cable for easy installation. The procedures for fixing these plates are as follow: 1) Measure the external diameter of the cable.

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2) Cut a semicircle on each half of the gland plates to match with the cable diameter as shown in Figure 6.9.1 for single three core cable. However in the case of three single core per-phase cable, the gland cutting will be as in Figure 6.9.2.

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3) Adjust the position of the power cable and mount the cable gland plates into position neatly. Tighten the fixing nuts securely. 4) If there is any gap between the power cable and the gland plate opening, wind some insulting tape around the cable neatly to close the gap.

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Figure 6.9.1 Gland Plate Cutting For One 3 Core Power cable

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CUT OUT FOR CABLE

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Figure 6.9.2 Gland Plate Cutting For 3 Single Core Per-hase Power Cable.

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CABLE SUPPORT

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INSULATION TAPE

GLAND PLATE

WINDING (IF NECESSARY)

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POWER CABLE '-

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Figure 6.9.3 Assembly Of Cable Gland Plate For One 3 Core Power Cable

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CABLE SUPPORT

GLAND fLATE

INSULATION TAPE WINDING (IF NECESSARY)

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Figure 6.9.4 Assembly Of cable Gland Plate For 3 Single Core Per-phase Power Cable

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6.10 Busbar Connections

6.1 0.1 The main and reserve bus bar can be accessed by loosening the 4 bolts and removing the bus bar cover as shown in diagram 6.1 0.1

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BUSBAR ACCESS

6.1 0.2 Remove the insulation cover and metal fitting and clean the contact surface. 6.10.3 Clean the surface of the busbar, bushing and metal fitting by cloth. 6.1 0.4 Fit the spacer between the main-busbar and connecting conductors of the farthest left or right switchgears. 6.1 0.5 Ensure that the bolts & nuts are inserted in the correct directions as shown by the arrow in Figure 6.1 0, 6.1 0.1, 6.10.2, 6.1 0.3. 6.10.6 Cover the connecting joint with the busbar cap.

I I

VIT-lOD Rev No: 0

19a

•

·--··-~·L-------------------··-----"----··-··---·-··-------···-·---~-----·------·-···"·---·------·----------·-···--·--------~----

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PROCESS !DESCRIPTION NO Check for

•

panel 3

NUT

~

WASHER - - - - - - - ,

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SPRING WASHER

BUSBAR SPACER----,~

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MAIN BUSBAR

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Mount the Guide pieces

FIT THE SPACER BETWEEN MAIN-BUSBARS AND CONNECTING CONDUCTOR.

WASHER~

supporter on the left side

EXPLANATION OR NOTE

THIS DRAWING SHOWS REAR VIEW)

received. Fix the Busbar

-~

.!

PICTURE OR SKETCH

supplied parts 2

. ·-----··

s'-c, 'O..;,S' /

(Rh)(B)

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on the 'i- "'"'

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bus bars 4

Insert the bus bars

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5

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supporter

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torque wrench (Torque

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CAUTION L BE CAREFUL ABOUT INSERTING DIRECTION OF BOLTS. OVERLAPPING PROCEDURE AND POSITION OF WASRERS, ETC.

\ _ _ SEE DETAIL 'D'

2. ARROWS IIEAN INSERTING DIRECTION.

_ _ _ _,"_L,__ c_e,_, _ _ __ ------------~

.... ----------

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DESCRIPTION Connection of busbars (refer sheet: No: 1 Detail A)

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Connection of busbars (refer sheet: No: 1 Detail B)

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PROCESS NO

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Connection of busbars (refer sheet: No: 1 Detail C) (/{~

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PICTURE OR SKETCH

Connection of busbars (refer sheet: No: I Detail D)

DROPPER ~USBAR - - - - - ,

$""'

" ' "-.,FIXING BOLT & NUT

MAIN BUSBAR

+----

BUSBAR SUPPORT

\0 .....,

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DESCRIPTION

EXPLANATION OR NOTE

PICTURE OR SKETCH

Connection of busbars (refer sheet: No: 1 Detail E)

DROPPER BUSBAR

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FIXING B!>L T & NUT

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"E"

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DESCRIPTION

EXPLANATION OR NOTE

PICTURE OR SKETCH

Connection of busbars (refer sheet: No: 1 Detail F)

FIXING BOLT &: NUT

ISOLATOR TO REYCHAM BUSBAR WITH C.T•

-

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EARTH SWITCH BUSBAR

CABLE TERMINATION BUSBAR

DETAIL 'F'

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6.11 Inspection After Installation Door Check the door to ensure that it can be opened and closed smoothly.

Tightness Of Joints 1) Check that no bolts and nuts are loosely connected. 2) Note: Bolts and nuts are marked using black during manufacture to enable detection of loose connection. Check that these markings are aligned. Retighten nut if necessary to restore the marking.

>-~-

Busbar Connection Check that all busbar connecting joints are tight. Insulation covers must be provided wherever necessary.

•

Cleaning 1) Look out for any tools or loose parts that have been left inside any compartment. 2) Clean any debris and dust inside and outside the cubicle.

I 7.0 OPERATION

7.1 VCB Operation The double bus bar VCB type utilised in this HICLAD I OD switchgear is of motorised spring charged, electrical closing mechanism. The charging motor starts immediately upon connection of

I

control DC supply and it stops when closing spring is fully charged. This charging operation repeats

I

of motor failure, manual charging is possible by using the manual charging handle provided.

I

automatically when the VCB is tripped, making it ready for the next closing operation. In the event

l

The VCB is of vertical isolation, horizontal withdrawal type on truck. At the service position, the main contacts of the moving truck are fully engaged with the main contacts of the fixed cubicle. These contacts are disengaged when the VCB is at the disconnected position. To select either the top or bottom busbar position of the switchgear, the arms of the VCB contact fingers can be raised

l I

or lowered manually using an elevating handle or by an electrical elevating motor (optional). To raise the VCB, turn the handle clockwise; to lower, turn it anti-clockwise. The status of the selected busbar position whether it is on the RAISED or LOWERED position is shown by a level indicator on the front of the VCB.

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VFf-lOD Rev No: 0

20

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CIRCUIT BREAKER AT RESERVE BUS POSITION

CIRCUIT BREAKER AT MAIN BUS POSITION

Figure 7.1.1 Vacuum CirciJ.it Breaker At Main And Reserve Bus Position Operation of the VCB can be done either locally or from a remote control panel by selecting the LOCAL/REMOTE (LR) switch mounted on the front of the metering door. By selecting "LOCAL,"

L

-

the VCB can be closed and opened using the TRIP/NORMAL/CLOSE (TNC) switch located on the metering door. Both the LR and TNC switches may be of lockable type (optional) to provide unauthorised operation of the VCB. The status of the VCB operation is indicated by a mechanical flag through a small opening on the front panel to show whether it is in the ON (RED) or OFF (GREEN) position. In addition to the mechanical indicators on the truck, two transparent openings are provided on the VCB

I

compartment door to allow checking of the VCB status without opening the door.

r

To operate the anti-condensation heater, turn the heater switch located inside the relay compartment to the ON position. An indicating light will turn on to show the status of the heater. Detailed description on the operation and maintenance of the VCB are given in another manual. Reference should be made to the relevant drawings whenever necessary.

VFI-lOD Rev No: 0

21

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;z

Raising And Lowering The Busbar

The vacuum circuit breaker can be elevated or lowered to the "Main" or "Reserve."

•••

u

--

---u"~c=Xeserve

bus bar is in the upper position and Main bus bar is at the lower position.

he elevating mechanism cannot be operated when the vacuum circuit breaker is in the "Test" or "Service" position. - - - - - 3 MANUAL RAISING & LOWERING VACUUM CIRCUIT BREAKER (FROM LOWER

TO UPPER) Refer to figure 7 .1.3

·-

t

LOCKING AND POSITION INDICATOR

•+

f.l1lii7

IIANLI'L CHARGING

C>'AAG(

+

-$ON-0ff

4+ DISCHAAGE

INDICATOR

•

MANU"CB KNOB OPERATING

$

MANUAL CB OPERATING KNOB

COUNTt:R

RESET

e lifT TO UNLOCK

~

Trip the VCB manually or electrically. Tum the interlock handle to the released position having handle kept .at released position. When the vacuum circuit breaker is withdrawn, the interlock handle is automatically engaged in the locked position. Vacuum circuit breaker is located at isolated position. Remove the socket cover for elevating handle. VFT-lOD Rev No: 0

21a

5) Move· the interlock lever to raise (item

)

6) Insert manual elevating handle socket to the operating shaft. 7) Turn the manual elevating handle clockwise. 8) Ensure that the elevating indicator meet the red line. This is the upper position. 9) Pull out the elevating handle socket from operation shaft. 10) Install cover socket for elevating handle on the front panel.

~-

11) When the vacuum circuit breaker is set from the upper busbar to the lower busbar position, use the same procedure.

;.~,

VFf-lOD Rev No: 0

2lb

.7.2 Earthing Switch The operating mechanism of the earthing switch is accessible from the front. By opening the VCB compartment door, the earthing switch mechanism is located on the left of the VCB. It can only be operated using handle provided. To close the earthing switch, insert the handle into the slot opening and push it downwards until a hard-knocking sound is heard when the earth switch is fully closed. Note that an interlock is provided between the earthing switch and the VCB as outlined in section 7.3. To open the earthing switch, the same operating handle is used. Push the handle upwards until the earthing switch is fully opened. The status of the earthing switch operation is indicated by a mechanical flag indicator attached to the operating mechanism to show whether it is ON or OFF. An indicating light may be provided on the front metering door as optional. -------·

ttl

7.3 Interlocks Several interlocking facilities have been incorporated to ensure safety of operation of the high voltage metalclad switchgear. These include the following: 1) The VCB truck cannot be inserted into its engaged or connected position when i) it is in the CLOSED condition. ii) the earthing switch is in the CLOSED position. 2) The VCB truck cannot be withdrawn or diconnected from its engaged position when it is in the CLOSED condition. 3) The VCB cannot be closed when i) it is not properly inserted into its engaged position. -,,

ii) it is not properly withdrawn to its disconnected or test position. Note: Items (3)(i) and (3)(ii) indicated that the VCB is in the intermediate position i.e. between

i

j

the connected and the disconnected positions. 4) The earthing switch cannot be closed when the VCB truck is not fully withdrawn to its disconnected position. 5) The VCB truck can only be inserted into its engaged position when it's selected busbar matches with the selected shutters of the fixed cubicle. Otherwise the shutter plates may be damaged if excessive .force is exerted.

8.0 SAFETY SHUTTERS Automatic safety will close to cover the main fixed contact stabs when the VCB. truck is f

-i

f l

'i i

.1

withdrawn from its engaged position. The top and bottom shutters are both labelled "BUSBAR" whil~

the middle one as "CIRCUIT" shutter. Operation of these shutters are independent of one

another. VFf-lOD Rev No: 0

22

t

When the VCB is located on the upper busbar positon, only the top two shutters will operate, while the bottom one remains stationary. When the VCB is engaged to the lower busbars, only the bottom two shutters will operate, while the top one stays stationary. Independant catches are fitted to enable the shutters to be held open for maintenance or testing purposes. Re-insertion of the VCB truck into the housing automatically cancels the catches. Each shutter can also be padlocked at the closed position for safety during maintenance.

9.0 TESTS AND COMMISIONING 9.1 General Prior to the delivery of the switchgear, routine factory tests would be carried out to detect any fault on materials and workmanship. These include check on cubicle dimensions, paintwork, wiring,

'---

insulation, resistance tests, power frequency voltage withstand test, relay injection test and general operation or functional test. Sitt! tests should be carried out before commisioning to ensure that the switchgear has been installed correctly and to detect any defect that may have been sustained during transportation. It is absolutely essential that tests and commissioning be performed only by competent persons to avoid damage or accident. Testing contractors are best experienced in site commissioning test. The following descriptions are given to serve as a guide only. Note: Test on the external power cables are not included here. Reference should be made to the relevant standards whenever necessary.

~

9.2 Physical Inspection 1) Check that the switchgears are installed in accordance with drawings. They should be securely bolted to the floor and all the external control and power cables are correctly terminated.

,.

2) Remove rear covers and check that the interconnecting busbars are securely fitted. Insulation covers should be fitted wherever necessary. 3) Check that the earthing busbars and terminations are installed correctly. 4) All dessicants should be remove. 5) Inspect all relays and meters and remove any packing. Check for zero setting for all indicating instruments.

l

.I

6) All external and inter-panel control wirings should be checked for correct termination and

~'

continuity.

l. l l

I~

t

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I~

i

1

VFT-lOD Rev No: 0

23

1

9.3 Isulation Resistance Test WARNING! Any solid state relay must be isolated during this test.

9.3.1 Power Circuit 1) This test should be carried out before power cable termination. Disconnect the cables temporarily, if neccessary. 2) Remove all PT and control fuses. 3) All CTs should be bridged using the CT shorting links terminals provided. 4) With all VCBs in open condition, measure the insulation resistance of ERYB-RYB using a suitable megger test set; usually 1kV or higher. )

5) Engage all VCB's and manually close all circuits. 6) Repeat the measurement of the insulation resistance for R-E, Y-E, B-E, R-Y, Y-B and B-R. The

til

value of the insulation resistance varies depending on the number of sections and the megger set used. But normally, the value should exceed 100 MegaOhm.

9.3.2 Control Circuit WARNING! Do not megger any solid state relay. Insulation resistance test for control circuit is optional. If necessary, use a 500V megger to measure the insulation resistance to earth. The insulation resistance should normally be greater than 1 MegaOhm.

9.4 Power Frequency Voltage Withstand Test WARNING! Any solid state relay must be isolated during this test. PRECAUTIONS: I) During this test, the surrounding area must be cordoned off and warning notice clearly positioned. 2) It is essential to earth the equipment under test after each and very test that has been performed.

9.4.1 Power Circuit 1) With all VCB's open, set up the same conditions as in iterris 9.3.1 (1) to (3). 2) Apply a high voltage to ERYB-RYB for 1 minute in accordance with IEC 298 and 694 standards. For service voltage of llkV, apply a test voltage of 28kV. The test is considered passed if there is no flash-over occurs.

24

VFf-lOD Rev No: 0

'

3) Now, close all VCBs and repeat item (2) forE IB-R, ERB-Y and ERY-B. 4) Megger test should be repeated as described in item 9.3.1(4) and (6). The value of insulation resistance may be slighty lower than that was recorded during the first megger test. NOTE: The frequency of the test voltage should be in the range of 25Hz to 1OOHz. If it is not practical to perform the test at the specified voltage, then voltages reduced according to the following table may be used for longer period as recommended by the BS 162 standard.

Duration of Test (minutes)

Precentage of 1 minute_ Test Voltage

1

100.0

2

8.3.5

3

75.0

4

70.0

5

66.6

10

60.0

15

57.7

J

II

I

J

Table 9.4.1.1 Power Frequency Test For Durations Exceeding 1 Minute

9.4.2 Control Circuit

,,

Pressure test on the control circuit if required, should be performed at a voltage equal to 2000V. The test is considered passed if no flash over occurs. Where electronic components are used in the control circuits, different testing procedures and values may be adopted subject to the agreement between the manufacturer and user.

9.5 Relay Injection Test ,«-

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Primary injection test on most relays are usually carried out before the switchgear leaves the factory. If internai wirings are not disturbed, the relays should function satisfactorily once they are set up for commissioning. It may be necessary to perform primary or secondary injeCtion

t~st

on site to

establish that no CTs, relays and wirings are damaged during transportation .

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1) Return alL CT shorting links to normal position.

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VFT-lOD Rev No: 0

25

2) Perform primary/secondary current injection test on all relays wherever possible to establish that the tripping time corresponds to that shown on the manufacturer's tripping characteristic curve.

9.6 Operation Test 1) Manually trip each VCB and withdraw it from its cubicle housing. Attach the Test Cord provided. 2) Set all relays according to the coordination data. 3) Select the REMOTE/LOCAL switch to "LOCAL." 4) Connect the test control supply and test the VCB for motor charging, electrical closing and tripping operations. 5) Check that the indicating lights function properly. /~

6) Repeat tripping test by operating the indication disc relays manually and bridge contacts if necessary. Reset all flag indicators. 7) Check operation of the earthing switch.

-

8) Check operation of the shutters. 9) Check that all interlock features function satisfactorily.

9. 7 Final Check 1) Check and ensure that no tools have been left inside the switchgear. Replace all covers. 2) Reconnect all power cables. 3) Inser. all PTs and control fuses. 4) Insert all VCBs into the fully engaged position. The switchgear is now ready for energisation.

I

10.0 MAINTENANCE I

lI

10.1 General

I

To ensure reliable and satisfactory service of the switchgear, it is recommended that through

I

maintenance be performed regularly. It will also serve to check that the switchgear is maintained in the safe operating conditions. Inspec;:tion should be made as soon as possible after the occurence of a fault on the circuit. The switchgear should not be placed into operation without a complete . check and tests after the clearance of the fault. A general guide is to refrain from changing exi.sting adjustments, unless absolutely necessary.

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VFT-lOD Rev No: 0

26

':_ ~-~ r:.:~.~

>·~~ ·.f

'·,··1.''···.

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2) Perform primary/secondary current injection test on all relays wherever possible to establish that the tripping time corresponds to that shown on the manufacturer's tripping characteristic curve.

:;1 ;~ ~

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'i

9.6 Operation Test

1) Manually trip each VCB and withdraw it from its cubicle housing. Attach the Test Cord provided. 2) Set all relays according to the coordination data. 3) Select the REMOTE/LOCAL switch to "LOCAL." 4) Connect the test control supply and test the VCB for motor charging, electrical closing and tripping operations. 5) Check that the indicating lights function properly. 6) Repeat tripping test by operating the indication disc relays manually and bridge contacts if necessary. Reset all flag indicators.

e

7) Check operation of the earthing switch. 8) Check operation of the shutters. 9) Check that all interlock features function satisfactorily. 9. 7 Final Check I) Check and ensure that no tools have been left inside the switchgear. Replace all covers.

2) Reconnect all power cables. 3) Insert all PTs and control fuses. 4) Insert all VCBs into the fully engaged position.

e

) The switchgear is now ready for energisation.

10.0 MAINTENANCE 10.1 General

To ensure reliable and satisfactory service of the switchgear, it is recommended that through maintenance be performed regularly. It will also serve to check that the switchgear is maintained in the safe operating conditions. Inspection should be made as soon as possible after the occurence of a fault on the circuit. The switchgear should not be placed into operation without a complete check and tests after the clearance of the fault. A general guide is to refrain from changing existing adjustments, unless absolutely necessary.

VFf-lOD Rev No: 0

26

Routine inspection should be conducted at regular intervals, normally not exceeding 6 months and at more frequent intervals in the case of important circuits. A maintenance program schedule should be planned to assist the personnel monitoring the service of the equipment. The frequency of the maintenance should be adjusted to take into account the environment, operating conditions, fault history and service liability. A brief sample of the maintenance program schedule is shown in Table 10.1.1.

Frequency 1 Daily 2 Monthly

-,.

Circuit Service General Indication Control supply Relay and Fuses Circuit Breaker and Meters Trip Circuit Relay and PTs

3. Half Yearly ~· :y~arly ______

-

Check Point Visual Inspection Healthy Test Inspection Operation Check Tripping Test Injection Test -

·--

-

Table 10.1.1 Sample Maintenance Schedule

For detailed maintenance of each component, reference should be made to the respective manufacturer's manual. The following sections describe the general procedures for routine maintenance.

10.2 Types Of Inspection 10.2.1 Daily Check

I

I

-

1) In daily inspection, no doors and covers are to be opened. The switchgear is checked from the outside for noise, smell or physical damage accordance with inspection schedule.

I l

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j l

-j

VFT-lOD Rev No: 0

27

2) When something abnormal is detected, identify the location and the degree of fault by opening the door of the the switchgear, if necessary. 3) Except when the trouble is expected to lead to an immediate malfunction of the switchgear, the

trouble is recorded as a reference data for the periodical or detailed inspection.

10.2.2

Periodical Check

1) Periodical check is carried out at intervals in accordance with the maintenance schedule.

2) It is done in principle with no voltage being applied and without dismantling the internal

components. Devices are checked from the outside by visual and touch in accordance with the inspection schedule.

IJ

CAUT!ON! If the main bus power supply is not shut down during inspection, use utmost caution for safety.

l

10.2.3 Detail (Extraordinary) Check Detail inspection should be performed when it becomes necessary as a result of daily or periodical check or when a fault has occured. 10.3 Methods Of Inspection

10.3.1 Using A Check List ~

1) Prepare a check list as shown in Table 10.3.1.1. Perform inspection on each item listed.

2) Mark or tick the "good" or "poor" column of check list depending on the result of the inspection. 3) When action is done to remedy fault or when it is necessary to do so, record it on the "Remedy/

I

Re.narks" column. Date

Name of Service

I

Cubicle External · part (door, ext cover) --

-

-·--

Temperature

Result Good Poor

Check Point

Part

Item

Weather

Checked By

Remedy!Remarks

Loose? Damaged? Noisy ? Stained ?

-~-

Table 10.3.1.1 Inspection Check List VFT-lOD Rev No: 0

28

"

10.3.2 Recording of Checks When during daily inspection, periodical inspection or detail inspection, some action was done to remedy the fault and the date. This record serves as reference data for the next maintenance and inspection or for future modification work.

10.4 Safety Precautions 10.4.1 Confirmation Of Power Voltage Shutdown Before checking the main, the following steps should be taken to ensure safety during inspection. l) Open/trip the relate circuit breaker to de-energise the circuit to be inspected.

__..

~.

2) Draw out the circuit breaker to the disconnected position and attach a warning sign "UNDER INSPECTION" to the breaker. . 3) Check using a voltage detector to ensure that no voltage is present and ground the circuit concerned by closing the earthing switch. 4) Lock the operation of the disconnecting switch, if any. If necessary padlock the safety shutter at the "CLOSED" position. 5) When there is a posibility of power being fed from the incoming panel or the bus-tie panel, take steps (2) to (4) for the bustie panel and the Incomer panel.

10.4.2 Precaution Against Residual Charges Before checking the cable connections or consider, if any, discharge the residual charges and ground them.

10.4.3 Removal Of Earthing Cable .-/~

After inspection is completed, the earthing cable that was temporarily removed for safety should be restored to the original condition.

10.5 Check On Paintwork The degree of rusting and peeling of paint surfaces depends on the site of installation, environment, the service condition and duration of use. During the periodical check, attention should be taken of the following points.

10.5.1 Rusting Of Metal Parts 1) Moving parts which, when rusted, would not rotate or slide smoothly.

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29

VFFIOD Rev No: 0

2) Those conducting parts which, when rusted, would change in contact resistance resulting in maloperation. 3) Springs and welded portions which, when rusted or eroded, would deteriorate in their mechanical strength. 4) Those portions which, when rusted, would lose beauty in appearance.

10.5.2 Peeling Of Paint or Coating Where the ambient conditions are severe, the painwork will deteriorate after within a few years of service. It is recommended that those portions where the paint is found to have been peeled off or the surface has become scorched, be touched-up or repainted as soon as possible.

11.0 TROUBLESHOOTING ~"""'

The swithgear was manufactured under strict quality control and has undergone various verification tests before despatch from the factory. However, should any trouble be found during daily or

-

periodical inspection, investigate the cause of trouble and take the necessary action according to the recommendations in Table 11.1. Table 11.1 Troubleshooting Check List

Part

Trouble

Possible Cause

Remedy

Shutters

1. Shutters damaged.

1. Repair damaged shutters.

do not

2. Moving parts poorly

2. Adjust moving parts &

close

adjusted & lubricating

apply lubricating oil.

oil deteriorated.

3. Clean moving parts.

3. Foreign matter trapped

e

in moving parts.

SHUTTERS Shutters

1. Padlock left locked.

1. Unlock the padlock.

do not

2. Shutters deformed.

2. Repair deformed shutters.

open

3. Moving parts adjusted

3. Adjust moving parts &

& lubricating oil deteriorated.

apply lubricating oil.

Conductor

1. Bolts on connections loose.

I . Retighten bolts.

connections

2. Overcurrent.

2. Limit current to rated value.

MAIN

overheated

CONDUC-

Ground

1. Insulators cracked.

I. Replace insulators.

TORS

fault or

2. Insulators stained with

2. Clean & dry insulators.

insulation

foreign matter or rain

resistance

water leaking.

drop

3. Plug small gaps & opening.

3. Instrusion of small animals. - - - - - - - L_

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VFT-lOD Rev No: 0

30

Part

DOOR

Trouble

Possible Cause

Handle

1. Wrong Key (if any)

I. Check key on

cannot be

2. Handle Internal

2. Lubricate key hole

unlocked

3. Handle internal

3. If in emergency, cut

mechanism faulty

off handle by saw.

Loose

I. Fixing screws loose.

l. Retighten the screws

handle

2. Internal mechanism worn out.

2. Replace the handle

I. Loose screws on hinge

l. Readjust the door & tighten.

Door

2. Hinge pin bent

warped and

3. Door deformed by external force

loose.

)

Remedy

2. Rectify the hinge pin. 3. Repair the deformed portion.

~~,

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Internal n01se

I. For srewsfixed partition

I. Partition plates vibrating due to

plates, retighten

electromagnet induction

screws.

(i) Loose screws

For welded partition

on partition plates. (ii) Welded partition plates dislocated. 2. Partition discharge due to

STRUCTURE

plates, reweld the

I

broken or parted portions. (i) After shutting down power

stainted surface of insulating

clean the surface of

material or moisture.

insulating material (ii) Turn on the heater to dry the air inside the cubicle.

--) Extinction

1. Bulb filament broken.

of indicating 2. Fuse or resistor burnt. lights

3. Poor contact of VCB auxiliary switch contacts.

CONTROL CIRCUIT

4. Auxiliary supply switch

i

2. Replace fuse or resistor. 3. Clean the auxiliary switch contacts. 4. Check MCB or fuse and wire terminal.

open circuited.

5. Check limits

5. Auxiliary switch

!

1. Replace bulb.

contacts shifted

switch contact

or faulty.

and operation.

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VFT-lOD Rev No: 0

31

Part

Trouble Continued simultaneou lighting of

Possible Cause I. Poor contact of VCB auxiliary switch contacts. 2. Contact resistance

Remedy 1. Clean auxiliary contacts. 2. Operated the auxiliary switch several time.

I I

both "ON"

increased due to dust

& "OFF"

contamination or

indicating

oxidation of contacts

lights.

(especially when they

CONTROL

are not operated for a

CIRCUIT

long period of time.) Poor operation

~-

1. Loose screws on terminal blocks.

1. Retighten screws on terminal blocks.

of control

2. Control circuit plug not

circuit in

properly connected.

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2. Reinsert the control circuit plug.

general. Poor

1. Auxiliary switch

operating of

contacts damaged by arc.

instruments

2. Contacts resistance increased

and relays.

due to oxidation or dust

1. Clean the contacting portions. 2. Operate contacts several time or replace contacts if necessary.

I

contamination. 1. VCB not fully inserted Does not close

2. Remote/Local selector switch not at right selection. 3. Auxiliary supply MCB open 4. Control circuit plug position left unconnected.

VACUUM

Does not

CIRCUIT

open

1. Insert completely to the connected position. 2. Change the switch to selected position. 3. Close MCB. 4. Connect control plug.

I

5. Control circuit voltage drop

5. Restore voltage.

6. Closing coil burnt.

6. Replace coil.

I

1. Local/Remote selector

1. Change the switch to

switch left unoperated.

selected position.

2. Auxiliary supply MCB open.

2. Close MCB.

3. Control circuit voltage drop.

3. Restore voltage.

4. Trip coil burnt.

4. Replace coil.

Cannot be

1. Wrong rating of VCB.

1. Insert the VCB of

inserted into

2. Lock fever does not

cubicle

lift up due to closed VCB. 3. Shutter operation

correct rating. 2. Tum off VCB. 3. Adjust the shutter mechanism lubricate moving parts.

imperfect:

VFT-lOD Rev No: 0

32

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